libceph: store timeouts in jiffies, verify user input
There are currently three libceph-level timeouts that the user can
specify on mount: mount_timeout, osd_idle_ttl and osdkeepalive. All of
these are in seconds and no checking is done on user input: negative
values are accepted, we multiply them all by HZ which may or may not
overflow, arbitrarily large jiffies then get added together, etc.
There is also a bug in the way mount_timeout=0 is handled. It's
supposed to mean "infinite timeout", but that's not how wait.h APIs
treat it and so __ceph_open_session() for example will busy loop
without much chance of being interrupted if none of ceph-mons are
there.
Fix all this by verifying user input, storing timeouts capped by
msecs_to_jiffies() in jiffies and using the new ceph_timeout_jiffies()
helper for all user-specified waits to handle infinite timeouts
correctly.
Signed-off-by: Ilya Dryomov <idryomov@gmail.com>
Reviewed-by: Alex Elder <elder@linaro.org>
diff --git a/net/ceph/mon_client.c b/net/ceph/mon_client.c
index 2b3cf05..0da3bdc 100644
--- a/net/ceph/mon_client.c
+++ b/net/ceph/mon_client.c
@@ -298,6 +298,12 @@
}
EXPORT_SYMBOL(ceph_monc_request_next_osdmap);
+/*
+ * Wait for an osdmap with a given epoch.
+ *
+ * @epoch: epoch to wait for
+ * @timeout: in jiffies, 0 means "wait forever"
+ */
int ceph_monc_wait_osdmap(struct ceph_mon_client *monc, u32 epoch,
unsigned long timeout)
{
@@ -308,11 +314,12 @@
while (monc->have_osdmap < epoch) {
mutex_unlock(&monc->mutex);
- if (timeout != 0 && time_after_eq(jiffies, started + timeout))
+ if (timeout && time_after_eq(jiffies, started + timeout))
return -ETIMEDOUT;
ret = wait_event_interruptible_timeout(monc->client->auth_wq,
- monc->have_osdmap >= epoch, timeout);
+ monc->have_osdmap >= epoch,
+ ceph_timeout_jiffies(timeout));
if (ret < 0)
return ret;